Research advances in animal distant hybridization

Distant hybridization refers to crosses between two different species or higher-ranking taxa that enables interspecific genome transfer and leads to changes in phenotypes and genotypes of the resulting progeny. If progeny derived from distant hybridization are bisexual and fertile, they can form a hybrid lineage through self-mating, with major implications for evolutionary biology, genetics, and breeding. Here, we review and summarize the published literature, and present our results on fish distant hybridization. Relevant problems involving distant hybridization between orders, families, subfamilies, genera, and species of animals are introduced and discussed, with an additional focus on fish distant hybrid lineages, genetic variation, patterns, and applications. Our review serves as a useful reference for evolutionary biology research and animal genetic breeding.     

Photosynthetic responses of Oryza sativa L. seedlings to cadmium stress: physiological,biochemical and ultrastructural analyses

In the present study, photosynthetic responses induced by cadmium stress in chlorophyll biosynthesis, photochemical activities, the stability of thylakoid membranes chlorophyll-protein complexes and the chloroplast ultrastructure of the cereal crop Oryza sativa L. were characterized. Cadmium inhibited the biosynthesis of chlorophyll by interfering with activity of δ-aminolevulinic acid dehydratase in the rice seedlings. For the photochemical activities analyses, the extent of the decrease in photosystem II activity was much greater than that in the PS I activity. The variations in the chlorophyll a fluorescence parameters also indicated that cadmium toxicity drastically affected the photochemistry of PS II. Biochemical analyses by BN-PAGE and protein immunoblot showed that cadmium toxicity considerably affected the stability of PS II-core, cytb ₆ /f, RuBisCO, PSI + LHCI and LHCII (Trimeric). We observed the rate of the thylakoid membranes protein degradation, was mainly at the level of RbcL, PsaA, Lhca1 and D1. In addition, the damages to chloroplast structure and thylakoid stacking analyzed by transmission electron microscopy were indicative of general disarray in the photosynthetic functions exerted by cadmium toxicity. These results are valuable for understanding the biological consequences of heavy metals contamination particularly in soils devoted to organic agriculture.     

Recent progress in nanobiocatalysis for enzyme immobilization and its application

Recent advances in nanotechnology have provided various nanoscale materials that can be used as support for enzyme immobilization. Nanobiocatalysis integrating the biocatalyst and nanoscale materials is drawing great attention as innovative technology. Nanobiocatalysis could achieve not only a much higher enzyme loading capacity and a significantly enhanced mass transfer efficiency, but also unbelievable stabilization. In this review, we will present and discuss the recent progress in nanobiocatalysis and its applications in the fields of bioelectronics, bioconversion, and proteomics.     

基于挥发性脂肪酸化学计量模型体外预测山羊瘤胃甲烷产量的精度

利用挥发性脂肪酸（VFA）的化学计量模型\[CH₄=0.5Ace-0.25Pro+0.5But-0.25Val,模型1,式中,CH₄、Ace、Pro、But和Val分别表示甲烷、乙酸、丙酸、丁酸和戊酸的产量\]预测瘤胃甲烷产量的精度.选用常见的10种化学成分差异显著的饲料原料（包括4种精饲料和6种粗饲料）进行体外模拟反刍家畜瘤胃发酵试验,测定发酵72 h后的VFA组成和CH₄产量.利用模型精度分析方法比较CH₄产量预测值与实测值间的差异.结果表明： 模型1估算的CH₄生成量普遍高于实测值,其偏差、斜率和随机误差分别为62.6%、11.7%和25.7%,固定误差＞70%.考虑到VFA代谢生成氢的80%用于合成CH₄,VFA化学计量模型表达为模型2\[CH₄= 0.8(0.5Ace-0.25Pro+0.5But-0.25Val)\].与模型1相比（均方预测误差=0.60）,模型2的预测精度大大提升(均方预测误差=0.18),模型2的偏差、斜率和随机误差分别为2.1%、5.7%和92.3%,固定误差＜10%.模型1认为VFA生成过程所产生的氢全部被甲烷菌用于合成CH₄,没有考虑氢代谢的其他途径,这是导致预测值大于实测值的一个重要原因.     

基于LMDI分解的厦门市碳排放强度影响因素分析

研究碳排放强度的变化趋势及其影响因素对于指导低碳城市建设具有重要意义。应用对数平均权重分解法(LMDI),基于厦门市2005—2010年各部门终端消费数据对碳排放强度指标进行因素分解,并将传统分析仅注重产业部门的能源碳排放,拓展到全面考虑产业部门和家庭消费的能源活动和非能源活动影响。研究结果表明:2005—2010年厦门市碳排放强度下降17.29%,其中产业部门能源强度对总碳排放强度变化影响最大(贡献63.07%),家庭消费能源强度是碳排放强度下降的主要抑制因素(-45.46%)。从影响效应角度看,经济效率对碳排放强度下降贡献最大,碳排系数减排贡献最小;从部门减排贡献角度看,第二产业贡献最大,家庭消费贡献最小。总体而言,厦门市未来碳减排重点部门在第二产业,优化产业结构和能源结构有较大减排潜力。     

Kinetics Absorption Characteristics of Ferrous Glycinate in SD Rats and Its Impact on the Relevant Transport Protein

Ferrous glycinate (Fe-Gly) maintains high bioavailability in animals, but its exact absorption mechanism is still unknown. Here, we studied on the absorption kinetics of ferrous glycinate and its impact on the relevant transport protein in Sprague-Dawley (SD) rats. A total of 72 SD rats (male, BW 100?±?6.25 g) were randomly allotted to three treatments. These treatments were perfused with 1 mL of normal saline, ferrous sulfate (FeSO₄), and ferrous glycinate (71.35 mg/L as iron) separately. Four rats were selected from each treatment for collection of blood from the tails at certain times (15, 30, 45, 60, 75, 90, 120, 240, and 360 min) after gavage. Moreover, other six rats selected from each treatment were slaughtered for sampling after gavage at 2, 4, and 6 h to evaluate the expression of intestinal transport protein. Pharmacokinetic parameters of iron were determined by one-compartmental analysis. Compared with FeSO₄, the peak plasma concentration of iron (C _max) is higher in the rats given gavage with Fe-Gly (P?<?0.05). Four hours after gavage with Fe-Gly, the expression of divalent metal transporter 1 (DMT1) in the duodenum is significantly decreased (P?<?0.05), but the expression of ferroportin 1 (Fpn1) is significantly increased (P?<?0.05). This study indicates that Fe-Gly as iron sources can be absorbed more and utilized faster than FeSO₄, and they had different effects on the expression of intestinal transport protein.     

Effects of different mineral supplements on fertilization of phenol-contaminated soils by Corynebacterium glutamicum

This study focused on the effects of different mineral supplements on the ability of Corynebacterium glutamicum to degrade phenol in contaminated soil and convert the phenol into useful amino acids. Three types of minerals including FeSO₄, MgSO₄, and MnSO₄ were added at several concentrations to C. glutamicum culture media containing 1% yeast extract prior to treating the soil samples with 4.24 mM phenol. The reactor was incubated at 30°C and 150 rpm for 3 days, and the treated soil was sampled daily and analyzed using gas chromatography for residual phenol and the amino acids produced. Additionally, a plant toxicity assay was employed to examine the fertilization of the phenol-contaminated soil after C. glutamicum treatment supplemented with the three minerals. Our results suggested that among various tested concentrations, 72 μM of iron showed a significant effect on the utilization of phenol by C. glutamicum for conversion to amino acids, therefore enhancing fertilization of the phenol-contaminated soil.     

2 型糖尿病神经病变患者血清IL-6、8-iso-PGF2α 检测及意义

目的:探讨2型糖尿病神经病变(DPN)患者血清IL-6、8-iso-PGF2α水平的变化及意义。方法:选择2型糖尿病患者伴神经病变的患者55例,单纯2型糖尿病不伴有神经病变的患者25例,另选25例体检健康者作为对照组。采用ELISA法分别测定各组血清IL-6、8-iso-PGF2α水平。结果:血清IL-6、8-iso-PGF2α水平在糖尿病组和糖尿病神经病变组均较对照组显著升高,差异具有统计学意义(P<0.01)。DN组8-iso-PGF2α较DM组显著升高,差异具有统计学意义(P<0.05);但IL-6在两组间差异无统计学意义(P>0.05)。结论:IL-6在糖尿病神经病变发病中的作用不能肯定。8-iso-PGF2α可能通过氧化应激作用参与糖尿病神经病变的发生发展。     

Cultivation of a highly enriched ammonia-oxidizing archaeon of thaumarchaeotal group I.1b from an agricultural soil

Nitrification of excess ammonia in soil causes eutrophication of water resources and emission of atmospheric N₂O gas. The first step of nitrification, ammonia oxidation, is mediated by Archaea as well as Bacteria. The physiological reactions mediated by ammonia‐oxidizing archaea (AOA) and their contribution to soil nitrification are still unclear. Results of non‐culture‐based studies have shown the thaumarchaeotal group I.1b lineage of AOA to be dominant over both AOA of group I.1a and ammonia‐oxidizing bacteria in various soils. We obtained from an agricultural soil a highly enriched ammonia‐oxidizing culture dominated by a single archaeal population [c. 90% of total cells, as determined microscopically (by fluorescence in situ hybridization) and by quantitative PCR of its 16S rRNA gene]. The archaeon (termed ‘strain JG1’) fell within thaumarchaeotal group I.1b and was related to the moderately thermophilic archaeon, Candidatus Nitrososphaera gargensis, and the mesophilic archaeon, Ca. Nitrososphaera viennensis with 97.0% and 99.1% 16S rRNA gene sequence similarity respectively. Strain JG1 was neutrophilic (growth range pH 6.0–8.0) and mesophilic (growth range temperature 25–40°C). The optimum temperature of strain JG1 (35–40°C) is > 10°C higher than that of ammonia‐oxidizing bacteria (AOB). Membrane analysis showed that strain JG1 contained a glycerol dialkyl glycerol tetraether, GDGT‐4, and its regioisomer as major core lipids; this crenarchaeol regioisomer was previously detected in similar abundance in the thermophile, Ca. N. gargensis and has been frequently observed in tropical soils. Substrate uptake assays showed that the affinity of strain JG1 for ammonia and oxygen was much higher than those of AOB. These traits may give a competitive advantage to AOA related to strain JG1 in oligotrophic environments. ¹³C‐bicarbonate incorporation into archaeal lipids of strain JG1 established its ability to grow autotrophically. Strain JG1 produced a significant amount of N₂O gas – implicating AOA as a possible source of N₂O emission from soils. Sequences of archaeal amoA and 16S rRNA genes closely related to those of strain JG1 have been retrieved from various terrestrial environments in which lineage of strain JG1 is likely engaged in autotrophic nitrification.